Question

Explain how the body is controlled in

i Ectotherms
ii Endotherms

Answer 1

I think you mean body temperature, right? Well, endothermal animals control their body temperature through their metabolic activity. If you get cold, for example, your hypothalamus sends signals to your muscles which begin to vibrate. Also, your brown fatty tissue is activated through noradrenalin (more effective in babies, since they have got more brown fatty tissue). This is a costly process. Thus, only higher evolved organisms can do that. see also: http://en.wikipedia.org/wiki/Endotherm

Ectotherms can not regulate body temperature through metabolism. There are some adaptions, like lizards exposing themselves to the sun to warm up, but in general, the lower the temperature, the lower the metabolic activity of Ectotherms. http://en.wikipedia.org/wiki/Ectotherm